After day of scrambling, no power outages Thursday

CPS asks for continued conservation.

Published 11:36 pm, Thursday, February 3, 2011

San Antonio avoided more planned power outages Thursday, but CPS Energy did ask that customers continue to conserve energy for as long as the frigid weather lasts.

Not all residents shared in the blackout pain equally Wednesday; some neighborhoods suffered through multiple power outages, while others were spared completely.

That mainly had to do with protecting circuits that include hospitals, International Airport and police and fire stations, but CPS CEO Doyle Beneby said the utility will look into ways to more finely separate those critical services and spread outages more equitably in the future.

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He also acknowledged that early communication about the outages could have gone more smoothly, although he reiterated that the utility had little advance warning from the state electrical grid operator to cut power. Though CPS had enough power for its customers, the state grid didn't.

CPS was responsible for cutting 74 megawatts. As it began doing so, the grid operator instructed CPS to double that reduction.

That was at 6:04 a.m. and by then, the media calls had begun, she said. Minutes later, the request to reduce power even further meant CPS' first message, which was that power would only be down in 15-minute increments, was already incorrect.

Conditions continued to change so rapidly, Lewis said, that updating the website or sending out an e-mail blast took a back seat to answering calls.

Just before 7 a.m., ERCOT sent out its first news release. By then, CPS had spoken to all local media outlets, and updated Facebook and Twitter, but still hadn't updated its website.

The morning's chaos will result in communication improvements.

CPS had been working to create an emergency alert system that could send messages directly to customers since last summer's storms knocked out power to thousands of homes, Lewis said; that effort now will be fast-tracked.

Some customers had to endure multiple outages that went beyond the rolling blackouts.

Some areas, especially those with a high percentage of electric-only households, were brought back online, Lewis said, only to trip back off, often more than once, because circuits were overloaded. That's why CPS asked people to shut down heaters and appliances while the power was off, and turn them back on over a period of minutes.

Why outages?

ERCOT also was criticized for its communication response.

CEO Trip Doggett said Thursday that events “unfolded quickly, and that often presents a challenge in communications,” but that the agency would look for ways to improve.

Statewide, about 50 generating units, representing about 7,000 megawatts that ERCOT had been counting on either tripped offline or were unable to come online, Doggett said. That's almost 10 percent of the grid's available capacity.

He blamed those downed units, not excess demand, as the reason behind the power shortage that forced it to call for rolling outages.

ERCOT lifted the emergency status for utilities across the state late Thursday morning, although Doggett said South Texas remained vulnerable.

“We continue to have plant outages in the Valley that concern us,” he said.

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The downed plants reported a variety of weather-related problems, like frozen pipes and valves and frozen control equipment. He said grid operators saw no particular pattern, either in location or reason for failure.

The shortage meant that at certain times, power that normally sells for about $100 a megawatt hour spiked to $3,000. That cost ultimately gets passed on to consumers. Lewis said CPS bought power on Wednesday but sold on Thursday, coming out slightly ahead.

When he was asked why ERCOT was not better prepared for weather that was predicted days in advance, Doggett punted.

“I'll have to let the grid owners of the generators speak to their specific issues,” he said.

Later, he said he didn't personally know the names of the downed units, but confidentiality would prohibit him from releasing them publicly anyway.

CPS' newest coal plant, Spruce 2, briefly tripped offline, but on the whole the utility's fleet added power to the state grid, Beneby said.

All its power plants were up and running at capacity Thursday, including its natural gas peaking units, as demand continued at record levels.

On Wednesday, CPS customers broke an August 2010 record for energy use in a 24-hour period, using 89,175 megawatt hours, even with the outages. The previous record of nearly 87,000 megawatt hours occurred during triple-digit heat.

Customers also used a record amount of natural gas, three times more than the average winter day.

That increased use means utility bills will be higher, especially compared to bills from the mild weather San Antonio had been enjoying.

The snow forecast for today isn't expected to affect service, but customers are urged to conserve, especially during the peak demand periods of 6 to 9 a.m. and 6 to 10 p.m.